‘Thanks to Corbyn the party has its largest ever membership, with a high proportion of young people who voted for remain busy campaigning at the grassroots.’Photograph: Frank Augstein/AP

Labour’s Brexit policy has been widely criticised on two main fronts, and rightly so. Its spokesman Keir Starmer doesn’t offer the electorate anything substantially different from what the Tories are proposing, and ducks a clear answer to the question of what a Labour government would do if parliament dislikes the final deal offered by the EU. Does Britain step into a void, the so-called cliff-edge route, or does it remain an EU member?

Even at this late stage, there is a chance for Labour to produce a better alternative. The manifesto should say that an incoming Labour government would abort the negotiations immediately. There will be no Brexit and no talks about how to achieve one.

The EU negotiators have repeatedly stated that, once it is outside the EU, Britain cannot expect to have the same deal, let alone a better one, than it does as a member. Angela Merkel restated the point in blunt terms on Thursday. So instead of embarking on a long and painful negotiating marathon when it is already clear the UK will end up worse off than it is now, Labour should promise to abandon the process immediately if it takes power in June.

Labour would transform the current campaign. Instead of just the Lib Dems and the Greens representing the 48%, Labour would be back on their side. The two-thirds of Labour voters who voted remain and are now in despair would be reinvigorated and many would campaign eagerly for a Labour victory. The danger of Labour voters haemorrhaging to the Greens and Lib Dems would be reduced. To the wider electorate Labour could present itself as the party doing most to lessen the chances of Scotland going to a second independence vote. Labour would be the party of stability while the Tories only offer recklessness.

The party would obviously arouse the scorn of the Tory media that would scream that Labour is defying democracy and holding last year’s referendum in contempt. But the claim that the referendum produced an irreversible verdict is phony. Just as a general election gives voters the right to revisit the choice of government that they made at the previous election, it also gives them the right to revisit a referendum result as long as the parties make clear that choosing or aborting Brexit is a key difference on offer.

The essence of democracy is that electorates are free to look again and change their minds. There is no need for a second referendum at some later stage. The coming general election offers a better opportunity.

The dominant narrative is that May is on course for a landslide victory, but May’s position is actually neither strong nor stable. She has been captured by her right wing. This election is really about her desire to escape by trying for a bigger Commons majority. She is also attempting to pre-empt the costs of Brexit before they bite. Inflation is already rising as imported goods go up in price. Real wages are stagnating; investment is on hold. All these indicators will be worse by 2020 when the election was meant to take place. With the zeal of the late convert, the prime minister who voted remain is hoping to rush Brexit into reality before public opinion turns decisively back to staying within the EU.

Of course Labour faces an uphill struggle. The Tory media are savaging Corbyn; they savaged Gordon Brown and Ed Miliband, and would have savaged Owen Smith had he won the leadership. Labour will have to canvass hard. But thanks to Corbyn the party has its largest ever membership, many of whom are also in Momentum, with a high proportion of young people who voted for remain busy campaigning at the grassroots.

In the post-industrial heartlands, as well as Wales where many Labour supporters voted Brexit, a promise to reverse it may provoke anger and cause trouble. But Labour’s switch to accepting Brexit since the referendum did not help it in the recent byelection in Copeland, which it lost to the Tories . So there is no certainty that switching back to the anti-Brexit stance that it took in the referendum will lose it more votes than it gains.

In any case, general elections work on a different dynamic. Labour can remotivate its core voters with its policies of social justice: free school meals; fairness for salary scales within companies; and the protection of the NHS and other public services, financed by investment and higher taxes on the rich.

But the best way to mobilise the crucial centre ground of British politics is to come out unambiguously with a promise to abort the move towards Brexit. As they prepare their manifesto, Labour’s leaders still have the time to be bold.